Side airbag device, vehicle seat provided with same, and method for manufacturing side airbag device

Abstract

This invention relates to a side airbag device stored inside a vehicle seat and fixed to a side frame. The device includes an airbag that expands and deploys to restrict an occupant; an inflator that supplies expansion gas to the airbag; and a bracket connected to the side frame that holds the airbag and the inflator. The airbag includes a prepush chamber having an inflator stored therein and mainly deploys inside of the side frame; and a main chamber connected to the prepush chamber and mainly deploys forward of the side frame. The bracket includes a first surface oriented in the forward direction of the vehicle; and a second surface oriented to the inside of the seat in the width direction of the vehicle. When the airbag is stored by being folded and/or rolled, at least the main chamber is disposed on the first surface of the bracket.

The invention claimed is: 
     
       1. A side airbag device for storage within a vehicle seat and securement to a side frame of the vehicle seat, the side airbag device comprising:
 an airbag for restraining an occupant when expanded and deployed; 
 an inflator for supplying expansion gas to the airbag, 
 a bracket retaining the airbag and the inflator and for connection to the side frame; and 
 a flexible cover member covering the airbag when folded, 
 wherein: 
 the airbag includes a pre-push chamber with the inflator stowed inside and deploys primarily on an occupant side of the side frame, and a main chamber that is connected to the pre-push chamber and deploys primarily toward a front of the side frame, the main chamber partitioned into a forward chamber and a rear chamber, 
 the bracket includes a first surface that faces a forward direction of vehicle travel and a second surface that faces a center side of the vehicle seat in a width direction, 
 and at least the main chamber is arranged adjacent to the first surface of the bracket when the airbag is in a folded and/or rolled stowed state, 
 the first surface of the bracket defines a first reaction surface directly opposing the main chamber in the forward direction of travel upon inflation of the airbag and the second surface defines a second reaction surface directly opposing the pre-push chamber in a lateral direction, and 
 wherein the first surface of the bracket is defined by a first plate and the flexible cover member has slits into which upper and lower portions of the first plate are inserted, respectively. 
 
     
     
       2. A side airbag device for storage within a vehicle seat and securement to a side frame of the vehicle seat, the side airbag device comprising:
 an airbag for restraining an occupant when expanded and deployed; 
 an inflator for supplying expansion gas to the airbag; 
 a bracket retaining the airbag and the inflator and for connection to the side frame, 
 the bracket including a first plate defining a first surface that faces a forward direction of vehicle travel and a second surface that faces a center side of the vehicle seat in a width direction; and 
 a flexible cover member covering the airbag when folded, 
 wherein the flexible cover member has slits into which upper and lower portions of the first plate are inserted, respectively. 
 
     
     
       3. The side airbag device according to  claim 2 , wherein:
 the airbag includes a pre-push chamber with the inflator stowed inside and deploys primarily on an occupant side of the side frame, and a main chamber that is connected to the pre-push chamber and deploys primarily toward a front of the side frame, the main chamber portioned into a forward chamber and a rearward chamber, 
 the bracket includes a first surface that faces a forward direction of vehicle travel and a second surface that faces a center side of the vehicle seat in a width direction, 
 and at least the main chamber is arranged adjacent to the first surface of the bracket when the airbag is in a folded and/or rolled stowed state, 
 the first surface of the bracket defines a first reaction surface directly opposing the main chamber in the forward direction of travel upon inflation of the airbag and the second surface defines a second reaction surface directly opposing the pre-push chamber in a lateral direction, and 
 a reference line at a rear edge of the rear chamber corresponds with an inclination angle at an upper region of the first surface of the bracket. 
 
     
     
       4. The side airbag device according to  claim 3 , wherein when in a stowed state, the pre-push chamber of the airbag is arranged on top of the second surface of the bracket. 
     
     
       5. The side airbag device according to  claim 3 , wherein:
 the rear chamber is configured such that at least one of a shoulder protecting region that protects a shoulder area, and a waist protecting region that protects a waist area, respectively of an occupant seated in the vehicle seat, reaches near a front end of the forward chamber. 
 
     
     
       6. The side airbag device according to  claim 5 , wherein the bracket includes a plate-shaped first plate with having the first surface and a plate-shaped second plate having the second surface, and the inflator is secured to the second plate. 
     
     
       7. The side airbag device according to  claim 6 , wherein the first plate of the bracket and the second plate of the bracket are nearly orthogonal to one another. 
     
     
       8. The side airbag device according to  claim 6 , wherein the rear chamber is configured such that the shoulder protecting region that protects the shoulder area of the occupant seated in the vehicle seat, reaches near a front end part of the forward chamber;
 the shoulder protecting region of the airbag is tucked in or folded toward a center of the main chamber using a first line as a crease, which is orthogonal to the reference line and extends from near the front end part of the shoulder protecting region to near a rear end of the rear chamber; 
 the airbag is folded or rolled from a front end side to a rear end side in a direction of the first line; 
 and the reference line is arranged along the first surface of the first plate when the airbag is retained on the bracket. 
 
     
     
       9. The side airbag device according to  claim 8 , wherein the folded or rolled lower end part of the airbag is further folded upwardly into a Z-shaped cross section with a second line and a third line that are parallel to the first line as creases. 
     
     
       10. The side airbag device according to  claim 6 , wherein the rear chamber is configured such that the waist protecting region that protects the waist area of the occupant seated in the vehicle seat, reaches near a front end part of the forward chamber;
 a lower end part of the waist protecting region of the airbag is tucked in or folded toward a center of the main chamber using a fourth line as a crease, which extends from near the front end part of the waist protecting region to near rear end of the rear chamber; 
 the tucked in or folded lower end part of the airbag is folded upwardly into a Z-shaped cross section so that a fifth line, which is orthogonal to the reference line, becomes the fold of a bottom edge; 
 the airbag is folded or rolled along the fifth line from a front end side to a rear end side; and 
 the reference line is arranged along the first surface of the first plate when the airbag is retained on the bracket. 
 
     
     
       11. The side airbag device according to  claim 10 , wherein the airbag is folded with an upper end part towards the center of the main chamber using a sixth line that is parallel to the fifth line as a crease, before being folded or rolled. 
     
     
       12. The side airbag device according to  claim 6 , wherein the rear chamber is configured such that the waist protecting region that protects the waist area of the occupant seated in the vehicle seat, reaches near a front end part of the forward chamber;
 a lower end part of the waist protecting region of the airbag is tucked in or folded toward a center of the main chamber using a fourth line as a crease, which extends from near the front end part of the waist protecting region to near a rear end of the rear chamber; 
 the airbag is folded or rolled along the fourth line from a front end side to a rear end side; and the reference line is arranged along the first surface of the first plate when the airbag is retained on the bracket. 
 
     
     
       13. The side airbag device according to  claim 12 , wherein an upper end part of the airbag is folded towards the center of the main chamber using a seventh line that extends in a front-rear direction as a crease, before being folded or rolled. 
     
     
       14. The side airbag device according to  claim 13 , wherein when a point is the point where the reference line and a front edge of the folded or rolled region intersect, a region forward of the reference line is folded rearward using an eighth line, which is orthogonal to the seventh line, as a crease. 
     
     
       15. The side airbag device according to  claim 14 , wherein the flexible cover member has a first through-hole to be engaged with a stud bolt of the inflator and a second through-hole to be circled around the airbag when folded and again engaged with the stud bolt. 
     
     
       16. A vehicle seat provided with the side airbag device according to  claim 2 . 
     
     
       17. The side airbag device according to  claim 3 , wherein the airbag is deployable such that the pre-push chamber is on a first lateral side of a partitioning part and partially rearward of the second surface, and the main chamber is on a second lateral side of the partitioning part and completely forward of the second surface.